Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method for compensating for Doppler shift on a non-terrestrial orthogonal frequency division multiplex (OFDM) network, the method comprising: determining, by a processing system of a user equipment (UE) instance, an absolute location of the UE instance, wherein the UE instance comprises: a transmitter, a receiver, and the processing system that comprises one or more processors; determining, by the processing system of the UE instance, for an angle between the UE instance and a satellite of the non-terrestrial OFDM network; determining, by the processing system of the UE instance, a relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network; determining, by the processing system of the UE instance, a frequency delta based on: a nominal uplink carrier frequency, the relative velocity, and the angle; and adjusting, by the processing system of the UE instance, a transmission frequency at which an uplink OFDM symbol is to be transmitted to the satellite of the non-terrestrial OFDM network using the frequency delta; and transmitting, by the transmitter of the UE instance the uplink OFDM symbol at the adjusted transmission frequency.
2. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 1 , wherein determining the relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network comprises: determining a velocity of the UE instance with respect to the Earth using global navigation satellite system (GNSS) measurements.
This invention relates to compensating for Doppler shift in non-terrestrial Orthogonal Frequency Division Multiplexing (OFDM) networks, particularly for satellite communications involving user equipment (UE). The problem addressed is the Doppler shift caused by the relative motion between the UE and the satellite, which degrades signal quality and synchronization in OFDM-based systems. The method involves determining the relative velocity of the UE with respect to the satellite to compensate for Doppler effects. This is achieved by measuring the UE's velocity relative to the Earth using Global Navigation Satellite System (GNSS) measurements, such as those from GPS or other satellite-based positioning systems. The GNSS-derived velocity data is then used to estimate the Doppler shift, allowing the system to adjust transmission parameters accordingly. This compensation ensures stable communication links despite the high mobility of the UE and the satellite. The technique is particularly useful in non-terrestrial networks where Doppler shifts are significant due to the high relative velocities involved. By leveraging GNSS measurements, the method provides an accurate and efficient way to mitigate Doppler-induced distortions, improving signal integrity and system performance. The approach can be applied to various satellite-based OFDM networks, including those used in broadband, IoT, and mobile communications.
3. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 2 , wherein the satellite is in a low earth orbit (LEO) or middle earth orbit (MEO).
This invention relates to compensating for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, specifically those involving satellites in Low Earth Orbit (LEO) or Medium Earth Orbit (MEO). Doppler shift occurs when the frequency of a transmitted signal changes due to relative motion between the satellite and ground stations, degrading communication performance. The method addresses this by dynamically adjusting signal parameters to mitigate the effects of Doppler-induced frequency shifts in LEO or MEO satellite networks. The method involves tracking the satellite's position and velocity to predict Doppler shift effects on the OFDM signal. Based on this prediction, the system adjusts the subcarrier spacing, symbol duration, or other OFDM parameters to compensate for the frequency shift. This ensures that the received signal remains within the expected frequency range, maintaining synchronization and reducing errors. The compensation may be applied at the transmitter, receiver, or both, depending on the network configuration. By dynamically adapting to the satellite's motion, the method improves signal integrity and reliability in non-terrestrial OFDM networks, particularly in LEO and MEO environments where Doppler shifts are more pronounced. This approach enhances communication performance in satellite-based systems where traditional terrestrial OFDM techniques are insufficient.
4. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 3 , wherein determining the relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network comprises: accessing data indicative of an orbit and orbital velocity of the satellite.
This invention relates to compensating for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, particularly for satellite communications involving user equipment (UE). The problem addressed is the Doppler shift caused by the relative motion between a satellite and UE, which can degrade signal quality and synchronization in OFDM-based systems. The method involves determining the relative velocity between the UE and the satellite to compensate for Doppler effects. This is achieved by accessing data that indicates the satellite's orbit and orbital velocity. By knowing the satellite's position and movement, the system can predict the Doppler shift experienced by the UE. This information is used to adjust the UE's signal processing, such as frequency correction or timing adjustments, to mitigate the impact of Doppler shift on communication performance. The approach leverages orbital data to dynamically compensate for Doppler effects, ensuring reliable signal transmission in non-terrestrial OFDM networks. The method is particularly useful in satellite communications where Doppler shift can significantly affect signal integrity due to high relative velocities between the satellite and ground-based UE.
5. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 1 , wherein the satellite is in a geostationary orbit.
A method compensates for Doppler shift in a non-terrestrial orthogonal frequency-division multiplexing (OFDM) network, specifically where the satellite operates in a geostationary orbit. The method addresses the challenge of maintaining signal integrity in high-frequency communications where Doppler effects caused by satellite motion can distort data transmission. By applying precise frequency adjustments, the method corrects the Doppler-induced frequency shifts, ensuring accurate signal reception and transmission. The compensation technique involves real-time monitoring of the satellite's position and velocity, followed by dynamic adjustment of the OFDM subcarrier frequencies to counteract the Doppler effect. This ensures stable communication links despite the relative motion between the satellite and ground stations. The method is particularly useful in geostationary satellite networks, where Doppler shifts, though smaller than in low-Earth orbit systems, still require compensation for reliable high-speed data transmission. The solution enhances system performance by minimizing bit errors and improving spectral efficiency, making it suitable for applications such as broadband internet, satellite TV, and military communications.
6. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 1 , further comprising: measuring a frequency of a downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
A method compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, particularly in satellite communications where Doppler effects distort signal frequencies due to relative motion between satellites and ground stations. The method involves measuring the frequency of a downlink OFDM symbol received from the satellite to detect Doppler-induced frequency shifts. This measurement allows the system to adjust the received signal's frequency to correct for the Doppler effect, ensuring accurate demodulation and data recovery. The technique is critical for maintaining signal integrity in high-mobility satellite networks where frequency shifts can degrade performance. By dynamically tracking and compensating for Doppler shifts, the method enables reliable communication in non-terrestrial OFDM systems, addressing challenges posed by satellite motion and varying signal paths. The approach may involve real-time frequency estimation and correction algorithms to mitigate the impact of Doppler effects on OFDM subcarriers, ensuring synchronization and minimizing errors in data transmission.
7. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 6 , further comprising: determining a frequency shift between an expected downlink frequency and the measured frequency of the downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
This invention relates to compensating for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, particularly those involving satellite communications. The problem addressed is the frequency distortion caused by Doppler effects when signals are transmitted between a satellite and ground-based receivers, which can degrade communication performance. The method involves measuring the frequency of a received downlink OFDM symbol from the satellite and comparing it to the expected downlink frequency. By determining the frequency shift between these two values, the system can compensate for the Doppler-induced distortion. This compensation ensures that the received signal aligns with the expected frequency, maintaining signal integrity and improving communication reliability in non-terrestrial networks. The technique is particularly useful in scenarios where satellites move relative to ground stations, causing frequency shifts due to the Doppler effect. By dynamically adjusting for these shifts, the method enhances the accuracy and efficiency of data transmission in satellite-based OFDM networks. The approach may be integrated into existing satellite communication systems to mitigate Doppler-related signal degradation.
8. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 7 , wherein adjusting the transmission frequency at which the uplink OFDM symbol is to be transmitted to the satellite of the non-terrestrial OFDM network is further based on the determined frequency shift between the expected downlink frequency and the measured frequency of the downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
This invention relates to compensating for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, particularly in satellite communications. The problem addressed is the frequency distortion caused by Doppler effects, which occurs when a satellite moves relative to a ground station, leading to mismatches between expected and actual downlink frequencies. This distortion can degrade communication quality and synchronization in OFDM-based satellite networks. The method involves adjusting the transmission frequency of uplink OFDM symbols sent to a satellite based on a measured frequency shift. Specifically, the system first determines the frequency shift by comparing the expected downlink frequency with the measured frequency of a received downlink OFDM symbol from the satellite. This measured shift is then used to adjust the uplink transmission frequency to compensate for the Doppler effect. By dynamically correcting the uplink frequency, the system maintains synchronization and minimizes errors in data transmission. The approach ensures that the uplink signals align with the satellite's expected frequency, improving signal integrity and reducing interference. This compensation is critical for reliable communication in non-terrestrial networks where Doppler shifts are significant due to high-speed satellite movement. The method can be applied in various satellite-based OFDM systems, including geostationary and low-Earth orbit (LEO) satellite networks.
9. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 1 wherein the UE instance communicates with the satellite of the non-terrestrial OFDM network using a 5G New Radio (NR) radio access technology (RAT).
A method compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, specifically for user equipment (UE) communicating with a satellite using 5G New Radio (NR) radio access technology (RAT). The method addresses the challenge of maintaining reliable communication in non-terrestrial networks, where high relative velocities between the UE and satellite cause significant Doppler shifts, leading to signal distortion and synchronization issues. The method involves adjusting transmission parameters to counteract the Doppler effect, ensuring proper signal alignment and reducing interference. This includes modifying subcarrier spacing, timing advance, and frequency synchronization to account for the Doppler-induced frequency shifts. The compensation technique is tailored for 5G NR, which supports non-terrestrial networks by incorporating flexible numerology and adaptive synchronization mechanisms. By dynamically adjusting these parameters, the method maintains signal integrity and throughput despite the Doppler shift, enabling stable communication between the UE and the satellite. The approach leverages the inherent capabilities of 5G NR, such as scalable OFDM numerology and precise timing control, to mitigate the impact of Doppler effects in high-mobility scenarios. This ensures reliable data transmission and reception in non-terrestrial environments.
10. The method for compensating for Doppler shift on the non-terrestrial OFDM network of claim 9 wherein the UE instance is a smartphone.
A method compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, specifically targeting smartphones as user equipment (UE). The technique addresses the challenge of maintaining signal integrity in high-mobility environments, such as satellite or high-altitude platform communications, where Doppler effects distort frequency due to relative motion between the transmitter and receiver. The method involves estimating the Doppler shift experienced by the smartphone, which may be moving at varying speeds, and applying a correction to the received signal to mitigate the distortion. This correction ensures accurate demodulation of the OFDM subcarriers, preserving data integrity. The approach may include adaptive algorithms that dynamically adjust compensation parameters based on real-time measurements of the smartphone's velocity and the network's frequency characteristics. By focusing on smartphones, the method accounts for the unique constraints of mobile devices, such as limited processing power and battery life, while optimizing performance in non-terrestrial networks. The solution enhances reliability for users relying on satellite or aerial communication systems, particularly in scenarios where terrestrial infrastructure is unavailable or unreliable.
11. A system for compensating for Doppler shift on a non-terrestrial orthogonal frequency division multiplex (OFDM) network, the system comprising: a satellite that is part of the non-terrestrial OFDM network; and a user equipment (UE) instance, comprising: a transmitter; a receiver; and a processing system comprising one or more processors, configured to: determine an absolute location of the UE instance; determine for an angle between the UE instance and the satellite of the non-terrestrial OFDM network; determine a relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network; determine a frequency delta based on: a nominal uplink carrier frequency, the relative velocity, and the angle; adjust a transmission frequency at which an uplink OFDM symbol is to be transmitted to the satellite of the non-terrestrial OFDM network using the frequency delta; and cause the uplink OFDM symbol to be transmitted at the adjusted transmission frequency to the satellite.
This invention relates to compensating for Doppler shift in non-terrestrial orthogonal frequency division multiplexing (OFDM) networks, particularly for satellite communications. The problem addressed is the frequency distortion caused by Doppler shift when user equipment (UE) communicates with satellites, which can degrade signal quality and synchronization in OFDM-based systems. The system includes a satellite and a UE device. The UE determines its absolute location and calculates the angle between itself and the satellite. It also measures its relative velocity with respect to the satellite. Using these parameters, along with the nominal uplink carrier frequency, the UE computes a frequency adjustment (delta) to compensate for Doppler shift. The transmission frequency of uplink OFDM symbols is then adjusted by this delta before sending the signal to the satellite. This ensures that the received signal at the satellite matches the expected frequency, maintaining synchronization and reducing errors. The UE's processing system handles these calculations and adjustments, enabling real-time compensation for Doppler effects in non-terrestrial OFDM networks. This approach improves communication reliability and efficiency in satellite-based OFDM systems.
12. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 11 , wherein the processing system of the UE instance being configured to determine the relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network comprises the processing system being configured to: determine a velocity of the UE instance with respect to the Earth using global navigation satellite system (GNSS) measurements.
A system compensates for Doppler shift in a non-terrestrial orthogonal frequency-division multiplexing (OFDM) network, particularly for user equipment (UE) communicating with satellites. The system addresses the challenge of maintaining signal integrity in high-mobility scenarios where Doppler effects distort OFDM subcarriers due to relative motion between the UE and the satellite. The UE includes a processing system that calculates the relative velocity between the UE and the satellite to adjust transmission parameters accordingly. To determine this velocity, the processing system uses global navigation satellite system (GNSS) measurements to derive the UE's velocity relative to the Earth. This velocity data is then used to estimate the Doppler shift caused by the satellite's motion, enabling precise compensation. The system ensures reliable communication by dynamically adjusting the OFDM waveform parameters based on the computed Doppler shift, mitigating signal degradation in non-terrestrial networks. The solution is particularly relevant for satellite communications where high-speed movement of the UE or the satellite introduces significant Doppler effects.
13. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 12 , wherein the satellite is in a low earth orbit (LEO) or middle earth orbit (MEO).
A system compensates for Doppler shift in a non-terrestrial orthogonal frequency-division multiplexing (OFDM) network, specifically for satellites in low Earth orbit (LEO) or medium Earth orbit (MEO). The system addresses the challenge of frequency shifts caused by relative motion between the satellite and ground stations, which disrupts OFDM signal integrity. The system includes a Doppler shift compensation module that dynamically adjusts the OFDM signal parameters to counteract the Doppler effect. This module estimates the Doppler shift based on the satellite's orbital position and velocity, then applies frequency correction to maintain synchronization between the satellite and ground stations. The system also incorporates adaptive modulation and coding techniques to further mitigate signal degradation due to Doppler-induced distortions. By compensating for Doppler shift in real-time, the system ensures reliable communication in non-terrestrial OFDM networks, particularly in LEO and MEO environments where Doppler effects are significant. The solution enhances signal quality, reduces bit error rates, and improves overall network performance in satellite-based OFDM communications.
14. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 13 , wherein the processing system of the UE instance is configured to determine the relative velocity of the UE instance with respect to the satellite of the non-terrestrial OFDM network comprises the processing system of the UE instance being configured to: access data indicative of an orbit and orbital velocity of the satellite.
This invention relates to a system for compensating for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, specifically addressing the challenge of maintaining signal integrity in high-mobility environments where Doppler effects distort communication. The system is designed for user equipment (UE) operating in satellite-based OFDM networks, where the relative motion between the UE and the satellite causes frequency shifts that degrade performance. The system includes a processing system within the UE that determines the relative velocity of the UE with respect to the satellite. This is achieved by accessing data that describes the satellite's orbit and orbital velocity. By leveraging this information, the UE can predict and compensate for Doppler-induced frequency shifts, ensuring stable communication links. The processing system may also incorporate additional techniques, such as adjusting transmission parameters or applying signal processing algorithms, to mitigate the effects of Doppler shift. The invention improves the reliability of non-terrestrial OFDM networks by dynamically adapting to the changing conditions caused by satellite motion and UE mobility. This is particularly useful in applications where high-speed data transmission is required, such as satellite communications, aerospace, and maritime systems. The system ensures that the UE can maintain synchronization with the satellite's OFDM signals despite the Doppler shift, enhancing overall network performance.
15. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 11 , wherein the satellite is in a geostationary orbit.
This invention relates to a system for compensating for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, specifically where the satellite is in a geostationary orbit. The system addresses the challenge of maintaining signal integrity in satellite communications by mitigating the effects of Doppler shift, which occurs due to relative motion between the satellite and ground stations. In a geostationary orbit, the satellite remains fixed relative to a point on Earth, but Doppler effects can still arise from factors such as ground station movement, atmospheric conditions, or orbital perturbations. The system compensates for these shifts by dynamically adjusting the frequency of transmitted and received signals to align with the expected Doppler-induced frequency deviations. This involves real-time monitoring of signal parameters, such as phase and frequency offsets, and applying corrective measures to maintain synchronization. The system may also incorporate predictive algorithms to anticipate Doppler shifts based on orbital mechanics and environmental data. By compensating for Doppler effects, the system ensures reliable communication in high-frequency OFDM networks, which are sensitive to frequency misalignment. The invention is particularly useful for applications requiring stable, high-data-rate transmissions in satellite-based networks.
16. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 11 , wherein the UE instance is further configured to: measure a frequency of a downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
A system compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, addressing signal distortion caused by relative motion between a satellite and user equipment (UE). The system includes a UE instance configured to measure the frequency of a downlink OFDM symbol received from the satellite. This measurement enables real-time adjustments to mitigate Doppler-induced frequency shifts, ensuring accurate signal demodulation and maintaining communication reliability. The UE may also estimate the Doppler shift based on the measured frequency and apply compensation techniques, such as frequency correction or adaptive filtering, to align the received signal with the expected frequency. The system operates in a non-terrestrial network, where satellites transmit OFDM signals to ground-based UEs, and Doppler effects are significant due to high relative velocities. By dynamically tracking and compensating for these shifts, the system enhances signal integrity and reduces errors in data transmission. The solution is particularly useful in satellite communications, where Doppler compensation is critical for maintaining synchronization and performance.
17. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 16 , wherein the instance of UE is further configured to: determining a frequency shift between an expected downlink frequency and the measured frequency of the downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
A system compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, addressing signal distortion caused by relative motion between satellites and user equipment (UE). The system includes a UE configured to measure the frequency of received downlink OFDM symbols from a satellite and compare it to an expected downlink frequency. The UE calculates the frequency shift between the measured and expected frequencies, enabling Doppler compensation. This adjustment ensures accurate signal demodulation despite Doppler effects, which arise from the high-speed movement of satellites relative to ground-based receivers. The system may also include additional components, such as a satellite transmitter and a network controller, to facilitate synchronization and signal processing. By dynamically adjusting for frequency shifts, the system improves communication reliability in non-terrestrial networks, where Doppler effects are more pronounced than in terrestrial systems. The solution is particularly relevant for satellite-based 5G and beyond-5G networks, where maintaining signal integrity is critical for high-speed data transmission.
18. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 17 , wherein the processing system of the UE instance being configured to adjust the transmission frequency at which the uplink OFDM symbol is to be transmitted to the satellite of the non-terrestrial OFDM network is further based on the determined frequency shift between the expected downlink frequency and the measured frequency of the downlink OFDM symbol received from the satellite of the non-terrestrial OFDM network.
A system compensates for Doppler shift in non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) networks, particularly for satellite communications. The system addresses the challenge of frequency distortion caused by relative motion between a user equipment (UE) device and a satellite, which disrupts signal synchronization and data transmission. The UE includes a processing system that measures the frequency of downlink OFDM symbols received from the satellite and compares it to the expected downlink frequency. The processing system then calculates the frequency shift due to Doppler effects. Based on this determined shift, the UE adjusts the transmission frequency of uplink OFDM symbols to the satellite, ensuring accurate synchronization and reliable communication. This compensation mechanism mitigates errors caused by Doppler-induced frequency deviations, improving signal integrity and network performance in non-terrestrial OFDM networks. The system dynamically adapts to varying Doppler shifts, maintaining synchronization even as the satellite and UE move relative to each other. This approach is particularly useful for satellite-based broadband and 5G non-terrestrial networks, where Doppler effects are significant due to high-speed satellite orbits and mobile ground stations.
19. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 11 wherein the UE instance communicates with the satellite of the non-terrestrial OFDM network using a 5G New Radio (NR) radio access technology (RAT).
A system compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, specifically addressing signal distortion caused by relative motion between a user equipment (UE) device and a satellite. The system operates within a 5G New Radio (NR) radio access technology (RAT) framework, ensuring compatibility with 5G standards. The UE communicates with the satellite using OFDM modulation, which is sensitive to Doppler effects due to high-speed satellite movement. The system includes mechanisms to detect and correct frequency shifts induced by Doppler, maintaining signal integrity and synchronization. This involves real-time adjustments to subcarrier frequencies and timing to counteract the Doppler-induced distortions. The solution ensures reliable communication in dynamic environments where traditional terrestrial networks may fail, such as in aerospace or maritime applications. By integrating 5G NR capabilities, the system leverages advanced modulation and error correction techniques to enhance performance in non-terrestrial scenarios. The compensation methods may include adaptive filtering, frequency tracking, and synchronization algorithms tailored for satellite communications. The overall goal is to provide seamless connectivity and high data rates despite the challenges posed by Doppler shift in high-altitude or space-based networks.
20. The system for compensating for Doppler shift on the non-terrestrial OFDM network of claim 19 wherein the UE instance is a smartphone.
A system compensates for Doppler shift in a non-terrestrial Orthogonal Frequency-Division Multiplexing (OFDM) network, specifically addressing signal distortion caused by high-speed movement between a user equipment (UE) device and a satellite. The system includes a UE instance, such as a smartphone, equipped with a Doppler compensation module that adjusts the received signal to account for frequency shifts induced by relative motion. The module estimates the Doppler shift based on the UE's velocity and the satellite's position, then applies a frequency correction to the OFDM subcarriers to maintain signal integrity. This ensures reliable communication despite the dynamic conditions of non-terrestrial networks, where Doppler effects are more pronounced than in terrestrial systems. The system may also include a synchronization mechanism to align timing between the UE and the satellite, further improving performance. By dynamically compensating for Doppler shifts, the system enables stable data transmission and reception for mobile devices in satellite-based OFDM networks.
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December 8, 2020
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